Update python-dotenv requirement from ~=0.20 to ~=1.0

Updates the requirements on [python-dotenv](https://github.com/theskumar/python-dotenv) to permit the latest version.
- [Release notes](https://github.com/theskumar/python-dotenv/releases)
- [Changelog](https://github.com/theskumar/python-dotenv/blob/main/CHANGELOG.md)
- [Commits](theskumar/python-dotenv@v0.20.0...v1.0.0)

---
updated-dependencies:
- dependency-name: python-dotenv
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -1,3 +1,3 @@
 pytest
-python-dotenv ~= 0.20
+python-dotenv ~= 1.0
 sendgrid ~= 6.9